The following invention relates to antennas and more specifically to broad band antennas of bicone design.
It is desirable to provide an omnidirectional vertically polarized antenna that operates over a wide frequency band. If this goal is met, programmable radios that operate over a wide frequency band can then be connected to a single antenna. The antenna could also be used for several radio systems, thereby reducing the number of antennas required.
It is typical to provide dedicated antennas for each radio frequency band used. These bands are typically 10 to 50% of the center frequency of operation. For example, military ultra high frequency (UHF) radios typically operate from 225 to 400 MHz. The antenna used for these radios operate only over this band. For radios operating over other bands, an antenna will be used for each of the radios.
Such dedicated antennas are commonly used on shipboard systems, resulting in an xe2x80x9cantenna farmxe2x80x9d on the ship""s topside and/or many antennas mounted on the ship""s mast. In those instances where broad band antennas are used, such as with electronic counter measure equipment, the antennas are usually based on class bicone antenna designs that are very large in size.
There is thus a need for a broad band antenna that can be used for a number of communication systems while at the same time is of minimal size.
The invention is a broad band antenna that uses a bicone antenna configuration as a feed transformer and exponentially tapered reflector fins to radiate the antenna""s energy. The fins function to reduce the traditional bicone antenna diameter. Reflection between the cones and the attached reflector fins as well as return loss are substantially reduced by wrapping the reflector fins with metallic foil.